1. Technical Field
The disclosure generally relates to insulating glass units and, more particularly, to devices and methods for sealing insulating glass units. Specifically, the disclosure relates to a patch and method of installing a patch at the joint of a spacer or other breaches in the seal in an insulating glass unit.
2. Background Information
The fenestration industry recognizes the importance of achieving an effective and enduring hermetic seal when manufacturing sealed insulating glass (IG) units. The seal is needed to minimize air intrusion and/or gas fill loss over the service life of the IG unit in order to optimize thermal insulation performance and durability.
The industry also recognizes the fact that any joint or discontinuity in an IG unit spacer is a break in the spacer's continuous seal which needs to be closed during production in order to provide the overall seal for the unit. The most common discontinuity is the start/stop location of the spacer where the first end of the perimeter spacer starts and second end of the perimeter spacer stops. These ends can touch each other or be closely spaced. Examples of IG unit spacer joints or discontinuities include 1) an angled joint when the start/stop joint is in a corner, 2) a straight joint when the start/stop joint is in a straight side, and 3) a splice in the spacer itself at a location other than the spacer start/stop application point. Examples of other seal breaches which need to be patched include capillary breather tube and wire insertion points, gas-fill holes and fasteners for internal IG components and the like.
The industry has published no general guidelines for closing discontinuities and other seal breaches. IG unit spacer discontinuity sealing has been customized depending on the specific spacer/sealant combination. The common practice has simply been to wrap a cover over the area to be patched. The typical cover has been either an adhesive-coated vapor barrier film or aluminum foil coated with PIB. It will be applied after one light has been installed, then either before or after the second light has been installed. In some applications, the wrapped cover application alone has been found to be an unreliable and ineffective seal. This cover helps to maintain the position of the spacer ends until the sealant is added to the outer channel.